1. Field of the Invention
The present invention relates to a display device.
2. Description of the Related Art
In recent years, along with an improvement of the information technology, needs for a thin display device are getting larger. For example, a thin display device such as a liquid crystal display device, a plasma display, and an organic EL display device has been put into practical use. Also, research and development for higher luminance and higher resolution of each type of thin display devices is actively performed. For example, as one of methods for enhancing luminance of an organic EL (Electro Luminescence) display device, a method to adopt a microcavity structure for an organic EL display device with a light emitting element structure of a top surface light emitting type has been proposed.
On an organic electroluminescence panel of a side-by-side method where a color of emitted light differs at each subpixel, when a microcavity effect is strengthened to enhance color purity of each color of RGB, a wavelength of light emitted from a light emitting layer changes according to a viewing angle and a chromaticity is shifted, which deteriorates a display quality. In other words, the viewing angle is narrowed down. Each of JP2005-284276A, JP2002-158095A, JP2009-272059A and JP2012-507110A discloses improving light extracting efficiency using a diffraction grating, but does not disclose widening the viewing angle.